Parts and functions of the digestive tract

D igestive System is a set of organs that rework harmoniously consumed meals into helpful substances, incorporate them via the absorption process and distinguish harmful substances. It’s a tube or tube that extends from the mouth to the anus and consists of a plurality of elements having totally different functions.



It is a cavity situated at the backside of the face and forming the first half. Digestive tract; it has chewing functions and meals separation


A cellular muscle-shaped structure situated in the oral cavity. It consists of two elements:

  • shifting part and
  • root.

The shifting half or tongue is roofed with a velvety mucosa having a lingual papilla divided into 5 teams:

  • shrub,
  • fungi,
  • filiform,
  • folium and
  • Hemispheric.


Salivary Glands

Salivary glands are organs that secrete gastrointestinal juice, which is a particular liquid of saliva, the chemical elements of the digestive tract, which lubricates the oral cavity and tongue.


It is a cylindrical structure by way of which meals passes by means of the stomach, which is situated at the front of the neck and crosses the again of the chest by way of the mediastinal until it reaches the membrane;

It consists of four elements: cervix, chest, diaphragm and stomach. Its size is 25 cm in a traditional grownup, its caliber shouldn’t be fixed and is observed flattened anteroposteriorly. In a relaxed state, it seems as an irregular cylinder as a consequence of physiological contraction: superior or crystalline narrowing, middle aortic cavernic narrowing, and membrane contraction

Improvements Retention of esophagus is a motor and sensitive. The engine consists of external and inner nerves. The outer nerves are pneumogastric or right and left vagus, which innervates the upper part of the esophagus. Inner are Auerbach's plexus, situated in clean muscle layers; regulate esophageal movement primarily in the decrease two-thirds.

The functions of the esophagus

They are the following:

  1. Transport fluids and solids from the pharynx.
  2. Avoid gastric regeneration.
  3. Produces secretions by way of glands protecting the walls

Swallowing mechanism

Swallowing has three phases:

  • oral,
  • mouth,
  • throat and
  • esophagus


passage from mouth to throat.

When the swallowed material enters the throat. the pharyngeal muscle mass of the pharynx contract and trigger peristaltic waves that rapidly unfold to the esophagus; Higher esophageal sphincter relaxes and permits gastrointestinal penetration into the esophagus

esophagus part

The peristaltic wave from the throat continues in the esophagus, carries the bolus, and maintains a high strain gradient alongside the organ. This wave is known as the main peristaltic wave and causes rest of the upper and decrease esophageal sphincters.

When main peristaltic waves are unable to carry a strong bolus via esophageal infiltration, secondary peristaltic waves happen that begin behind the weight loss plan.

The aged have tertiary non-propulsive peristaltic waves, and patients with esophagus or hernia have obscure, irregular waves situated at the backside of the esophagus. He doesn't know his job.


It’s a hollow, muscular formed member, which is shaped bag into the tube and which is sustained underneath the above esophagus and duodenum. It’s situated at the prime of the stomach cavity and is situated in a large part of the epigastrium and the left hypochondria. It has two entrance and rear elements; two curvature, small and giant, and two excessive, higher and lower; higher or heart opening and worse or pyloric opening.

  • There are three totally different gastric glands with open secreting channels in the gastric glands:
  1. Pyloric glands: situated in the gastric anthrax: they produce mucus, an important issue for the absorption of vitamin B12, gastrin produced from G-cells of the pylori glands. .
  2. CNS: They’re found in the physique's stomach and produce mucus, digestive tract, and substances with hormonal properties.
  3. Cardiac Glands: Branched Glands consisting of Mucous membranes

Watering. Arteries are organized in a vascular circuit shaped by the artery arc in a smaller curvature and the other by a higher curvature.

The arc of the much less curvature artery consists of the stomach coronary artery, the limb body branch and the pylori artery of the artery of the liver. The arc of the larger curvature artery consists of the proper gastrointestinal tract, the department of the gastroduodenal artery and the left gastrointestinal artery, the branch of the spleen artery.

Gastric Mucosa Blood Circulation: Gastric Mucosa Circulation Supplies It Mechanism Of Resistance To Hydrochloric Acid, which promotes healing and therapeutic of ulcers. These capillaries have a skinny and phenotypic wall with excessive permeability, favoring the circulation of vitamins and bicarbonate, all of which regulate the autonomic nervous system, gastrin, vasopressin and prostaglandins. All of these elements type the Davenport's definition of gastric mucosal barrier, which is answerable for gastric mucosa property to stop acid diffusion from gastric lumen in relation to wall thickness, which in turn defends the corrosive impact of self-secretion. 19659021] Innovations Three embedded methods adhere to the stomach:

  • parasympathetic,
  • snug and
  • intramural plexes. Nerve Pulses
    Sympathetic have delicate functions, and synapses launch radiating brokers comparable to: adrenaline and noradrenaline. It incorporates celiac and photo voltaic lenses
    The intramural nerve reminiscence is situated on two layers of the inner organs: Meissner's submucosa and Auerbach's muscular. They’re two intramural networks whose process is to revive physique mobility, with substances reminiscent of histamine and acelilcolina

    Stomach properties

    It has a number of digestive course of functions:

    1. Motorboat. 19659007] Secretary: Hydrochloric acid, pepsin hormones
    2. Tank and regulation of evacuation of meals to be consumed
    3. Changing and adapting chemical composition, pH and focus of food
    4. Antianemia by pure manufacturing contributing to vitamin B12 absorption
    5. absorption of vitamins
    6. Elimination of sure poisonous products

    As a result of its significance, the secretory perform is explained

    . Abdomen gastric secretion is nervous and hormonal. The first reaches the stomach by means of the vagus-nerve into the nerve-nerve that innervates the mucus and other glands of the abdomen. Humoral stimulus generates G-cell-released gastrin

    Gastrin reaches parietal cell receptors and stimulates secretion of hydrochloric acid and pepsin, gastric motility, and increased blood circulate. In gastric secretion, along with gastrin, cholecystokinin, gastric launch peptide (bombesin), intestinal vasoactive peptide, gastric inhibitory peptide, secrecin, neurotensin and somatostatin are involved. Other newly recognized peptides embrace:

    • enkephalin, [19659007] pancreatic polypeptides,
    • intestinal peptide YY,
    • glucagon,
    • calcitonin corticotropin releasing factor.

    The stomach excretory exercise is considerable and the fluid excreted in the fasting individual ranges from 500 to 1500 ml. Natural and inorganic elements are present in the stomach; It’s clear and colorless and accommodates water, hydrochloric acid, sodium, potassium, calcium, phosphate, bicarbonate and sulphate, enzymes, pure factor and mucus

    1. Pepsin. Proteolytic enzyme in gastric acid
    2. Renina..Milk milk.
    3. Lipase enzyme that opens lipids
    4. Gelatinase enzyme that liquefies gelatin
    5. Lysozyme Open carbohydrates
    6. Urea It is derived from gastric mucosa and bacterial cells
    7. Carbonic anhydrase. Essential position in the formation of hydrochloric acid

    into the duodenum

    It is the first part of the small intestine. It has a horseshoe shape, 25 cm lengthy and 12 cm in diameter. It’s divided into four elements: 1st, 2nd, 3rd and 4th. doses:

    • 1. dose or duodenal lamp. It extends from the pylori to the gallbladder neck
    • 2. half. In the mild of this part, there are two eminences or papillae referred to as caruncles: the largest or Vater, with a standard and pancreatic canal or Virsung, and a decrease carousel, the place the Santorini canal ends.
    • 3. part.
    • Part 4. It passes from mesenteric vessels to the duodenojejuna (Treitz angle)

    Watering. The duodenum receives irrigation of the artery of the liver that radiates the gastroduodenal, and its innervation comes from the solar lumen and overwhelming mesenteric gangli.

    Duodenal functions

    duodenum has three functions: engine, and excretion of

    1. Motor perform contractions of segments allows it allows for makeroiduilla meals and pancreatic secretions mixing of the fingers and to facilitate the absorption. Peristaltic contractions permit the spider to progress to jejunum
    2. . Brunner's glands produce giant amounts of mucus in response to tactile, chemical and nervous stimuli. These glandular major process is to guard the content material of the secretion of gastric mucosa
    3. Endocrine perform of the duodenal mucosa of a plurality of release of hormonal substances, with stimulants, anti-impact and combined, to make sure harmony of the digestive course of. 19659047] 1. As a secret. A polypeptide that stimulates pancreatic secretion into water and bicarbonate or hydrolactic provokes the bile and blocks the acid stomach.
      2. Cholecystokinin-pancreozyme. It causes the secretion of pancreatic enzymes, narrows the gallbladder and barely stimulates gastric motility and secretion

      Polypeptide gastric inhibitor. It inhibits acid secretion and stimulates the release of insulin by beta cells of the pancreatic islets of Langerhans
      four. Enteroglukagon. Prevents acid gastric secretion and intestinal motility
      5. Enteroxintin. Stimulates acidic abdomen secretion when amino acids come into contact with the mucosa
      6. Different hormones. Vasoactive peptide, somatostatin, substance P, neurotensin and insulin-dependent glucose-dependent peptide inhibit gastric acid secretion

      t enterocytes, which is free to limit referred to as "brush border" as a result of they have a small eyelashes or mikrovillat directed to the intestinal lumen. It’s a wool epithelium of nice significance for digestive and absorbent functions.
      Intestinal mucosal projections are wild-jejunum, ileum, the lumen, that are manifold and advanced in the jejunum and the ileum extending projection. Keckring valves. In these wild, there’s a cylindrical brush edge epithelium, mucus-producing goblet cells and endocrine cells referred to as enterocromaffins and leukocytes
      Watering. Arteries come from the overwhelming mesenteric, stomach aorta and superior mesenteric plexus.

      Functions of Jejunileon

      The primary functions are: motor, secretion, absorbent and endocrine

      Allows the mixing of intestinal contents.

      Sekretointi. When the chyme reaches the intestine, chemical and tactile stimuli assist the mucous membranes to excrete the mucosa and type the intestinal tract. This juice consists of secretions launched in the intestines of the digestive course of and serves to offer last digestion of the food prior to absorption.

      1. Peptidase They convert polypeptides to amino acids
      2. Disacaridase. They convert disaccharides into monosaccharides: maltase, isomaltaaasiksi, in sucrose, lactase
      3. Intestinal lipase Open neutral fat glycerine and fatty acids
      4. amylase. Corrects the 1.4 linkage of glucose in starch and cereal starch.
      5. Amylopectin It types disaccharides (maltose) from complicated sugars reminiscent of maltotrione, alpha-detrines and oligosaccharides.

      Absorbent Perform The absorption perform is characterised by a constructive stability between insorption and exorption
      . as in the case of amino acids; passive transport, as in the case of fat, and facilitated transport, as with sure monosaccharides
      In this operation, there are several elements, reminiscent of substrate preparation; contact with the absorbent surface; particular transportation of the substrate akin to vitamin D and calcium;
      villiquinin endocrine hormone stimulates the rhythmic contractions of the small intestine. Other hormones are released, corresponding to succinin, cholecystokinin, pancreozyme and glucagon


      It is handled in a separate chapter


      Gallbladder is a organ that acts as a bile container of liver and consists of water, natural substances (bile salts, phospholipids, cholesterol, natural matter) and conjugated bilirubin) and inorganic (chlorine, bicarbonate and potassium).

      The functions of gallbladder

      It has two primary functions: [19659024] Bile concentration (gall bladder absorbs giant amounts of water and condenses its contents 6 to 10 occasions.)

    4. Collective evacuation. (It occurs by contraction of the vesicle in response to cholecystokinin and the rest of the Oddi sphincter.)

    By way of the duodenal catheter, 3 totally different bile are obtained:

    • Bile A cohort; It’s Canarian yellow
    • Bile B, coming from the gallbladder; It’s dark brown
    • Bile C, which flows from the liver;

    The gallbladder in the absorption mechanism
    Bile salts, phospholipids and cholesterol are associated with bile in the type of micelles; Subsequently, ldl cholesterol dissolves in the bile.
    Bile performs an essential and very important position in the absorption and cleavage of fat. Dietary fats, when it enters the gut, attacks the pancreatic lipase that breaks down into fatty acids and monoglycerides which are insoluble and can’t be absorbed.
    Bile salts which are secreted by the bile, have a detergent and have a water-soluble portion and a non-polar moiety that’s soluble in fats. These molecules are compressed and type micelles. Stated micellaraggregaateilla has the property that they’re soluble in water-insoluble lipid material, so that the fatty acids and monoglycerides are dissolved micelliin so that they’re absorbed and transported by way of the intestinal cell.



Pancreas is a body that has digestive and hormonal activity. It consists of three elements:

  • a head that’s intently linked to a worse vena cava and the proper kidney blood,
  • a physique situated in entrance of the decrease vein of Cava and the aortic artery
  • and a tail that’s proportional to the spleen and left kidney

] Pancreas Perform

It has two functions: exocrine and endocrine.

  • Exocrine perform. The pancreas secretes pancreatic juice wealthy in bicarbonate and proteolytic enzymes (endopeptidases, exopeptidases, nucleases and trypsin), lipolytic and aminolytic, pancreozymes and polypeptides.

Effect of pancreatic juice.

  1. On account of its bicarbonate content material, it neutralizes the strongly acid abdomen that extends into the duodenum
  2. By means of enzymes, it makes the breakdown of fat, carbohydrates and proteins
  3. .
  4. it inhibits the absorption of iron in the small intestine mucosa (speculation) [1965913million] Endocrine Perform This perform is answerable for hormoninsuliinia whose primary function is to facilitate the combustion of glucose [19659131] Colon [19659003] It’s a phase of the giant intestine that extends cecumista anus. It is 1.5 m lengthy, although it could possibly attain 2 m and consists of segments: blind, rising colon, transverse column, descending, sigmoid, rectum and anus.

    Sock has a cylindrical extension, a vermiform attachment that he communicates via a small hole. It has a Bauhin-Morgagn ileo-valve that separates it from the groin


    The colon has three fundamental functions:

    1. It regulates the ileosecal valve and the outcome of the content to the colon.
    2. it facilitates the reabsorption of hydrosaliinin and mixing of the contents of the colon
    3. or mass of the propulsive movements take away and transport the bulk of the contents of the giant gut

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